Three-dimensional models are sometimes used to assist in the placement or use of a device when such placement or use is not easily observable or practical. For example, in medical procedures, three-dimensional models presented on a graphical user interface are used to assist in the placement and use of medical devices as part of diagnosis or treatment of patients. An example of such a medical procedure carried out with the assistance of a three-dimensional model presented on a graphical user interface is the use of a catheter for radio frequency (“RF”) ablation to terminate certain arrhythmias in the heart.